Answer:
Step-by-step explanation:
Let the function that shows the given situation is,
Where x is the number of years.
Initially, x = 0,
According to question f(0) = 4
Thus, a = 4
Since, each year the number of fish is increased by 3 times,
That is, for x = 1, f(1) = 12
But,
⇒
⇒ b = 3
By putting the values of a and b in the above function,
We get,
Which is the required function that shows the given situation.
⇒ Option D is correct.